Possible mitochondrial dysfunction and its association with antiretroviral therapy use in children perinatally infected with HIV.

BACKGROUND: Mitochondrial dysfunction has been associated with both human immunodeficiency virus (HIV) infection and exposure to antiretroviral therapy. Mitochondrial dysfunction has not been widely studied in HIV-infected children. We estimated the incidence of clinically defined mitochondrial dysfunction among children with perinatal HIV infection. METHODS: Children with perinatal HIV infection enrolled in a prospective cohort study (Pediatric AIDS Clinical Trials Group protocols 219 and 219C) from 1993 through 2004 were included. Two clinical case definitions of mitochondrial dysfunction, the Enquête Périnatale Française criteria and the Mitochondrial Disease Classification criteria, were used to classify signs and symptoms that were consistent with possible mitochondrial dysfunction. Adjusted odds ratios of the associations between single and dual nucleoside reverse-transcriptase inhibitor use and possible mitochondrial dysfunction were estimated using logistic regression. RESULTS: Overall, 982 (33.5%) of 2931 children met 1 or both case definitions of possible mitochondrial dysfunction. Mortality was highest among the 96 children who met both case definitions (20%). After adjusting for confounders, there was a higher risk of possible mitochondrial dysfunction among children who received stavudine regardless of exposure to other medications (odds ratio, 3.44 [95% confidence interval, 1.91-6.20]) or who received stavudine-didanosine combination therapy (odds ratio, 2.23 [95% confidence interval, 1.19-4.21]). Exposure to lamivudine and to lamivudine-stavudine were also associated with an increased risk of mitochondrial dysfunction. CONCLUSIONS: Receipt of nucleoside reverse-transcriptase inhibitors, especially stavudine and lamivudine, was associated with possible mitochondrial dysfunction in children with perinatal HIV infection. Further studies are warranted to elucidate potential mechanisms of nucleoside reverse-transcriptase inhibitor toxicities.

Vitamins are Indeed Vital Amines: A Discussion of 3 Deficiencies With Neurologic Manifestations.

Optimal functioning of the human nervous system depends on a constant supply of nutrients, vitamins, and minerals. In the developed world, nutritional deficiencies are relatively rare and infrequently present with neurologic manifestations. These neurologic disorders can be mistaken for inflammatory and/or autoimmune phenomena. This manuscript describes 2 pediatric cases with neurologic signs/symptoms arising from vitamin deficiencies-(1) optic neuropathy and (2) Wernicke encephalopathy associated with a Guillain-Barre-like pattern of weakness. The 2 cases and the subsequent discussion of vitamin A, B1, and B12 deficiencies underscore the value of taking a thorough dietary history and emphasize risk factors for these 3 nutritional deficiencies.

Carnitine in parenteral nutrition.

Several new functions or metabolic uses of carnitine and improvements in assessment of carnitine status impact carnitine dosing recommendations. Carnitine dosing will likely be customized for patients at different stages of the life cycle and for patients with dysfunction of different organs. Nutrition supplementation of carnitine should be 2-5 mg x kg(-1) x day(-1) and be administrated via the route used for administration of macronutrients. Pharmacologic supplementation of carnitine should be 50-100 mg x kg(-1) x day(-1) and be reserved for the removal of toxic compounds from the body.

Safety and Efficacy of Atorvastatin in Human Immunodeficiency Virus-infected Children, Adolescents and Young Adults With Hyperlipidemia.

BACKGROUND: Human immunodeficiency virus (HIV)-infected children receiving antiretroviral therapy (ART) have increased prevalence of hyperlipidemia and risk factors for cardiovascular disease. No studies have investigated the efficacy and safety of statins in this population. METHODS: HIV-infected youth 10 to <24 years of age on stable ART with low-density lipoprotein cholesterol (LDL-C) ≥130 mg/dL for ≥6 months initiated atorvastatin 10 mg once daily. Atorvastatin was increased to 20 mg if LDL-C efficacy criteria (LDL-C < 110 mg/dL or decreased ≥30% from baseline) were not met at week 4. Primary outcomes were safety and efficacy. RESULTS: Twenty-eight youth initiated atorvastatin; 7 were 10-15 years and 21 were 15-24 years. Mean baseline LDL-C was 161 mg/dL (standard deviation 19 mg/dL). Efficacy criteria were met at week 4 by 17 of 27 (63%) participants. Atorvastatin was increased to 20 mg in 10 participants. Mean LDL-C decreased from baseline by 30% (90% confidence interval: 26%, 35%) at week 4, 28% (90% confidence interval: 23%, 33%) at week 24 and 26% (90% confidence interval: 20%, 33%) at week 48. LDL-C was less than 110 mg/dL in 44% at week 4, 42% at week 12 and 46% at weeks 24 and 48. Total cholesterol, non high-density lipoprotein (non-HDL)-C and apolipoprotein B decreased significantly, but IL-6 and high-sensitivity C-reactive protein did not. Two participants in the younger age group discontinued study for toxicities possibly related to atorvastatin. CONCLUSIONS: Atorvastatin lowered total cholesterol, LDL-C, non HDL-C and apolipoprotein B in HIV-infected youth with ART-associated hyperlipidemia. Atorvastatin could be considered for HIV-infected children with hyperlipidemia, but safety monitoring is important particularly in younger children.

In vivo quantification of intraventricular hemorrhage in a neonatal piglet model using an EEG-layout based electrical impedance tomography array.

Intraventricular hemorrhage (IVH) is a common occurrence in the days immediately after premature birth. It has been correlated with outcomes such as periventricular leukomalacia (PVL), cerebral palsy and developmental delay. The causes and evolution of IVH are unclear; it has been associated with fluctuations in blood pressure, damage to the subventricular zone and seizures. At present, ultrasound is the most commonly used method for detection of IVH, but is used retrospectively. Without the presence of adequate therapies to avert IVH, the use of a continuous monitoring technique may be somewhat moot. While treatments to mitigate the damage caused by IVH are still under development, the principal benefit of a continuous monitoring technique will be in investigations into the etiology of IVH, and its associations with periventricular injury and blood pressure fluctuations. Electrical impedance tomography (EIT) is potentially of use in this context as accumulating blood displaces higher conductivity cerebrospinal fluid (CSF) in the ventricles. We devised an electrode array and EIT measurement strategy that performed well in detection of simulated ventricular blood in computer models and phantom studies. In this study we describe results of pilot in vivo experiments on neonatal piglets, and show that EIT has high sensitivity and specificity to small quantities of blood (<1 ml) introduced into the ventricle. EIT images were processed to an index representing the quantity of accumulated blood (the 'quantity index', QI). We found that QI values were linearly related to fluid quantity, and that the slope of the curve was consistent between measurements on different subjects. Linear discriminant analysis showed a false positive rate of 0%, and receiver operator characteristic analysis found area under curve values greater than 0.98 to administered volumes between 0.5, and 2.0 ml. We believe our study indicates that this method may be well suited to quantitative monitoring of IVH in newborns, simultaneously or interleaved with electroencephalograph assessments.

Presence of arachidonoyl-carnitine is associated with adverse cardiometabolic responses in hypertensive patients treated with atenolol.

INTRODUCTION: Atenolol, a commonly prescribed ß blocker for hypertension, is also associated with adverse cardiometabolic effects such as hyperglycemia and dyslipidemia. Knowledge of the mechanistic underpinnings of these adverse effects of atenolol is incomplete. OBJECTIVE: We sought to identify biomarkers associated with risk for these untoward effects of atenolol. We measured baseline blood serum levels of acylcarnitines (ACs) that are involved in a host of different metabolic pathways, to establish associations with adverse cardiometabolic responses after atenolol treatment. METHODS: Serum samples from Caucasian hypertensive patients (n = 224) who were treated with atenolol in the Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) study were interrogated using a quantitative LC/MS assay for a large number of unique ACs in serum. For the 23 ACs that were detected in serum from ≥80 % of all patients, we conducted linear regression for changes in cardiometabolic factors with baseline AC levels, baseline cardiometabolic factors, age, sex, and BMI as covariates. For the 5 ACs that were detected in serum from 20 to 79 % of the patients, we similarly modeled changes in cardiometabolic factors, but with specifying the AC as present/absent in the regression. RESULTS: Among the 28 ACs, the presence (vs. absence) of arachidonoyl-carnitine (C20:4) was significantly associated with increased glucose (p = 0.0002), and was nominally associated with decreased plasma HDL-C (p = 0.017) and with less blood pressure (BP) lowering (p = 0.006 for systolic BP, p = 0.002 for diastolic BP), after adjustment. CONCLUSION: Serum level of C20:4 is a promising biomarker to predict adverse cardiometabolic responses including glucose and poor antihypertensive response to atenolol.

A Call to Action to Bring Safer Parenteral Micronutrient Products to the U.S. Market.

The American Society for Parenteral and Enteral Nutrition (A.S.P.E.N.) started an intensive review of commercially available parenteral vitamin and trace element (TE) products in 2009. The chief findings were that adult multi-TE products currently available in the United States (U.S.) provide potentially toxic amounts of manganese, copper, and chromium, and neonatal/pediatric multi-TE products provide potentially toxic amounts of manganese and chromium. The multivitamin products appeared safe and effective; however, a separate parenteral vitamin D product is needed for those patients on standard therapy who continue to be vitamin D depleted and are unresponsive to oral supplements. The review process also extended to parenteral choline and carnitine. Although choline and carnitine are not technically vitamins or trace elements, choline is an essential nutrient in all age groups, and carnitine is an essential nutrient in infants, according to the Food and Nutrition Board of the Institute of Medicine. A parenteral choline product needs to be developed and available. Efforts are currently under way to engage the U.S. Food and Drug Administration (FDA) and the parenteral nutrient industry so A.S.P.E.N.'s recommendations can become a commercial reality.

Practical approach to metabolic assessments in the pediatric human immunodeficiency virus outpatient clinic.

BACKGROUND: Metabolic assessment is not a routine part of the care of pediatric HIV-positive patients in the outpatient setting, although research studies are demonstrating an increasing prevalence of metabolic abnormalities in this population. Addition of metabolic assessments to routine clinic care can be hindered by the perception that collection of the data needed for the assessments will need too much clinic time and too many clinic resources to be practical. METHODS: A method to provide metabolic assessments using minimal clinic resources while offering educational opportunities for university students was developed and implemented at the University of Florida Pediatric Immunology and Infectious Diseases weekly clinic. The success rate of metabolic assessment data collection from all clinic patients and the impact of data collection on the flow of clinic activity were monitored for a 12-month period. RESULTS: The metabolic assessment team interviewed 87% of all patients who came to the 454 clinic during the 12-month period and performed a complete metabolic assessment for 75% of the HIV-positive patients interviewed. Addition of metabolic assessments to the routine care of each patient did not result in any noticeable adverse effect on the functionality of the clinic. CONCLUSIONS: Addition of metabolic assessments to the routine clinic care of pediatric HIV positive patients can be an educational opportunity for university students and provide the clinic staff with changes in parameters indicative of metabolic abnormalities and without noticeable changes in maintaining the patient schedule at each clinic.

Translating the basic knowledge of mitochondrial functions to metabolic therapy: role of L-carnitine.

Mitochondria play important roles in human physiological processes, and therefore, their dysfunction can lead to a constellation of metabolic and nonmetabolic abnormalities such as a defect in mitochondrial gene expression, imbalance in fuel and energy homeostasis, impairment in oxidative phosphorylation, enhancement of insulin resistance, and abnormalities in fatty acid metabolism. As a consequence, mitochondrial dysfunction contributes to the pathophysiology of insulin resistance, obesity, diabetes, vascular disease, and chronic heart failure. The increased knowledge on mitochondria and their role in cellular metabolism is providing new evidence that these disorders may benefit from mitochondrial-targeted therapies. We review the current knowledge of the contribution of mitochondrial dysfunction to chronic diseases, the outcomes of experimental studies on mitochondrial-targeted therapies, and explore the potential of metabolic modulators in the treatment of selected chronic conditions. As an example of such modulators, we evaluate the efficacy of the administration of L-carnitine and its analogues acetyl and propionyl L-carnitine in several chronic diseases. L-carnitine is intrinsically involved in mitochondrial metabolism and function as it plays a key role in fatty acid oxidation and energy metabolism. In addition to the transportation of free fatty acids across the inner mitochondrial membrane, L-carnitine modulates their oxidation rate and is involved in the regulation of vital cellular functions such as apoptosis. Thus, L-carnitine and its derivatives show promise in the treatment of chronic conditions and diseases associated with mitochondrial dysfunction but further translational studies are needed to fully explore their potential.

A.S.P.E.N. position paper: recommendations for changes in commercially available parenteral multivitamin and multi-trace element products.

The parenteral multivitamin preparations that are commercially available in the United States (U.S.) meet the requirements for most patients who receive parenteral nutrition (PN). However, a separate parenteral vitamin D preparation (cholecalciferol or ergocalciferol) should be made available for treatment of patients with vitamin D deficiency unresponsive to oral vitamin D supplementation. Carnitine is commercially available and should be routinely added to neonatal PN formulations. Choline should also be routinely added to adult and pediatric PN formulations; however, a commercially available parenteral product needs to be developed. The parenteral multi-trace element (TE) preparations that are commercially available in the U.S. require significant modifications. Single-entity trace element products can be used to meet individual patient needs when the multiple-element products are inappropriate (see Summary/A.S.P.E.N. Recommendations section for details of these proposed modifications).

Development of the piglet neonatal intensive care unit for translational research.

The piglet is an important animal model in biomedical research; many aspects of its anatomy, physiology and metabolism are similar to those of the human neonate. The authors describe a neonatal intensive care unit (NICU) for piglets. This unit allows researchers to model neonatal care in the NICU and can be used for a range of research studies. The authors hope that the model they describe can serve as a template for other investigators who would like to design their own piglet NICUs.

Acylcarnitines: role in brain.

l-carnitine is present in mammalian cells as free carnitine and acylcarnitines. The acylcarnitine profile has been shown to be useful in identifying inborn errors of metabolism and to be altered under different metabolic conditions. While carnitine's most widely known function is its involvement in beta-oxidation of fatty acids, it may also have other roles in metabolism. The importance of acylcarnitines in tissues with high rates of beta-oxidation such as heart and muscle is intuitive. However, acylcarnitine and carnitine supplementation have resulted in beneficial effects in the treatment of various neurological diseases, even though fat is not the major fuel for brain. Recent data indicate new, multifactorial roles for acylcarnitines in neuroprotection. Brain acylcarnitines can function in synthesizing lipids, altering and stabilizing membrane composition, modulating genes and proteins, improving mitochondrial function, increasing antioxidant activity, and enhancing cholinergic neurotransmission. Currently a relatively small subset of acylcarnitines is usually investigated. More research is needed on the use of acylcarnitines in the treatment of neurological diseases using a list of acylcarnitines encompassing a wide range of these molecules. In summary, carnitine is not merely a cofactor in beta-oxidation, but rather it has many known and yet to be discovered functions in physiology.

Associations of proinflammatory cytokine levels with lipid profiles, growth, and body composition in HIV-infected children initiating or changing antiretroviral therapy.

OBJECTIVES: To measure proinflammatory cytokines (PIC) in HIV-infected children beginning or changing antiretroviral therapy (ART), evaluating associations with virologic, immunologic, serum lipid, growth, and body composition measures, markers of growth hormone action and glucose metabolism. METHODS: Forty-nine prepubertal HIV-infected children had measurements of viral load (VL), CD4 lymphocyte count and percentage, serum lipids, apolipoprotein AI/B, IGF-1, IGFBP-1, and IGFBP-3, anthropometry, bioelectrical impedance analysis, TNF-α, IL-1 ß, and IL-6 at baseline and 48 weeks of ART. RESULTS: Baseline levels were detectable (>0.1 pg/mL) for IL-1 ß in 28 of 48, and for TNF-α and Il-6 in all 49 children. TNF-α decreased with ART (P < 0.001) and IL-6 demonstrated a similar trend (P = 0.065). Children with 48-week VL <400 copies/mL had greater declines in TNF-α (mean 45%) than subjects with higher VL (5%; P = 0.009). Each 10% improvement in CD4% was associated with 26% lower TNF-α (P = 0.002) and 31% lower IL-6 (P = 0.016). Greater reductions in TNF-α were associated with lower total/HDL cholesterol ratio (P = 0.003) at week 48. CONCLUSIONS: In HIV-infected children initiating or changing ART, PIC were detectable at baseline and decreased over 48 weeks. Better immunologic responses were associated with greater reductions in TNF-α and IL-6. Reductions in TNF-α were associated with improved total/HDL cholesterol ratio.

Detection of intraventricular blood using EIT in a neonatal piglet model.

We have developed a sensitive EIT protocol for detection of intraventricular bleeding. A common model of human neonates is the neonatal piglet. We used our method to test the sensitivity of our method and device to small amounts of blood-like fluid injected near the left and right ventricles of a piglet cadaver. Comparing blood-like fluid detection in open an closed piglet skulls, we found that we could detect amounts of blood less than 0.5 ml, which is smaller than that required for our target of detecting grade II intraventricular hemorrhages in human neonates.

Morphologic and metabolic abnormalities in vertically HIV-infected children and youth.

OBJECTIVE: To compare the distribution of lipid and glucose abnormalities and altered fat distribution among vertically HIV-infected patients and controls. DESIGN: Cross-sectional multicenter study on HIV-infected (HIV-positive) patients, 7-24 years of age, stratified by Tanner stage and protease inhibitor use (protease inhibitor, n = 161 and non- protease inhibitor, n = 79) and seronegative controls (HIV-negative, n = 146). METHODS: Measurements included fasting lipids, glucose, insulin, 2-h oral glucose tolerance test, dual-energy X-ray absorptiometry, anthropometry, and antiretroviral therapy and medical histories. Multiple linear regression models were used to compare distributions between HIV-positive and HIV-negative groups. RESULTS: Both HIV-positive groups had long exposures to antiretroviral therapy. Protease inhibitor and nonprotease inhibitor groups had similar current CD4 cell count and HIV-1 RNA, but the protease inhibitor group had lower nadir CD4 cell count, higher peak HIV-1 RNA, and more advanced Centers for Disease Control disease stage. In adjusted analyses, both HIV-positive groups had significantly lower mean Z scores for height, weight, BMI, and total and limb fat than the HIV-negative group. Mean triglycerides were significantly higher and high-density lipoprotein cholesterol lower in both HIV-positive groups relative to the HIV-negative group. The protease inhibitor group also had significantly higher mean total, low-density lipoprotein, and non-high density lipoprotein cholesterol. Mean fasting insulin was higher in both HIV-positive groups, and 2-h glucose and insulin were higher in the protease inhibitor group. Ritonavir was associated with increasing dyslipidemia and altered glucose metabolism. CONCLUSION: In a large group of vertically HIV-infected children and youth with extensive antiretroviral therapy exposure, height, weight, and total and limb fat were lower than in controls. There was a high prevalence of lipid abnormalities among those on protease inhibitors and evidence of developing insulin resistance, factors that may accelerate lifetime risk for cardiovascular disease.

Insulin-like growth factor-1 and lean body mass in HIV-infected children.

OBJECTIVES: To describe insulin-like growth factor-1 (IGF-1) and insulin-like growth factor-1-binding protein-1 (IGFBP-1) and IGFBP-3 in HIV+ children before and after initiating or changing antiretroviral therapy and to evaluate association of growth and body composition to growth factors at baseline and over time. METHODS: Ninety-seven prepubertal HIV+ children aged 1 month to younger than 13 years were observed over 48 weeks after beginning or changing antiretroviral therapy. Serum IGF-1, IGFBP-1, and IGFBP-3 were measured and compared with age- and sex-specific norms. Anthropometric measures were compared as follows: subjects vs matched children from (a) the National Health and Nutrition Examination Survey to generate z scores and (b) HIV-exposed, uninfected children from Women and Infants Transmission Study; and subjects with normal vs abnormal IGF-1 and IGFBP concentrations at baseline. Anthropometric changes were compared for children whose IGF-1 level normalized vs remaining subjects. Multivariate analysis adjusting for sex, race, and baseline age evaluated associations between anthropometry and IGF-1 and IGFBP concentrations. RESULTS: In multivariate analysis, lower baseline IGF-1 and IGFBP-3 were associated with lower mean weight, height, mid-arm muscle circumference, and mid-thigh circumference z scores. Twenty-four percent of children had a low IGF-1 level at baseline, 50% of whom normalized IGF-1 on study. Children whose IGF-1 normalized had greater increases in mean mid-arm muscle circumference z score (1.00 vs -0.03, P = 0.029), but a trend toward lesser mean height increase (P = 0.082) than remaining subjects. Likewise, in comparison to controls from Women and Infants Transmission Study, mean mid-arm muscle circumference also increased more in children whose IGF-1 normalized (P = 0.024) but mean height changed less (P = 0.003). Fifty-five percent of children had elevated IGFBP-1 at baseline, 69% of whom normalized. CONCLUSIONS: IGF-1 increases and IGFBP-1 decreases in HIV-infected children upon initiation or change in antiretroviral therapy. Improved muscle mass, but not linear growth, is associated with normalized IGF-1 concentration. These findings suggest that IGF-1 may merit evaluation as a potential therapeutic strategy to improve lean body mass in HIV-infected children.

Lipid and glucose alterations in HIV-infected children beginning or changing antiretroviral therapy.

OBJECTIVE: The objective of this study was to describe lipid profiles and glucose homeostasis in HIV-positive children after initiating or changing antiretroviral therapy and their associations with viral, immune, antiretroviral therapy, and growth factor parameters. METHODS: Ninety-seven prepubertal HIV-positive children aged 1 month to <13 years were observed for 48 weeks after beginning or changing antiretroviral therapy. Fasting lipid panels, serum glucose, insulin, insulin-like growth factor-1 and binding proteins-1 and -3, plasma viral load, and CD4% were measured. Each child was matched on age, gender, and race/ethnicity to children from the National Health and Nutrition Examination Survey, used to give z scores for each child's lipid values. Multivariate regression was used to evaluate the association of changes in z scores over 48 weeks with suppression of HIV-1 RNA, change in CD4% and growth factors, and antiretroviral therapy, adjusted for entry z score, CD4%, log(10) HIV-1 RNA, Centers for Disease Control and Prevention category, and total fat and cholesterol dietary intake. RESULTS: Lipid, apolipoprotein, and insulin levels all increased significantly by 48 weeks. Multivariate analysis of changes demonstrated that increased HDL and decreased total-HDL cholesterol ratio were associated with CD4% increase and with insulin-like growth factor-1, which increased to normal (versus remained stable or became low) over 48 weeks. Total cholesterol levels increased among children who achieved HIV-1 RNA of <400 copies per mL. Antiretroviral therapy regimens that included both a protease inhibitor and a non-nucleoside reverse transcriptase inhibitor were associated with greater increases in total-HDL cholesterol ratio than regimens that contained a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor but not both. CONCLUSIONS: In these HIV-positive children with predominantly mild-to-moderate disease, initiation or change in antiretroviral therapy was associated with significant increases in multiple lipid measures and insulin resistance. Favorable lipid changes were associated with CD4% increases, suggesting a protective effect of immune reconstitution on atherosclerosis, and with increased insulin-like growth factor-1 levels, supporting the theory that reduced growth hormone resistance may be a mechanism by which lipid profiles are improved. Finally, antiretroviral therapy regimens that contain both a non-nucleoside reverse transcriptase inhibitor and a protease inhibitor are associated with worse lipid profiles than regimens that contain 1 but not both of these drug classes.

Carnitine and lipid metabolism

Carnitine, a short-chain nitrogen containing carboxylic acid, is found in meat and dairy foods. Carnitine aids in a shuttle process that makes long-chain, fatty-acid coenzyme A derivatives available for B-oxidation. Normal healthy adults have adequate carmitine stores and do not require dietary carnitine. However, neonates, chronically and critically ill patients with decreased muscle and liver carnitine store seen to benefit from carnitine supplementation to enhance their tolerance of metabolic stress